LHC: No Smashing Until Spring

Photonics.comSep 2008
GENEVA, Sept. 23, 2008 -- Investigation into the cause of a large helium leak at the Large Hadron Collider (LHC) and repairs to the magnets that quenched during the leak mean the atom smasher won't restart until spring 2009, officials at CERN, the organization hosting the particle accelerator, announced Tuesday.

"Coming immediately after the very successful start of LHC operation on 10 September, this is undoubtedly a psychological blow," said CERN Director General Robert Aymar. "Nevertheless, the success of the LHC's first operation with beam is testimony to years of painstaking preparation and the skill of the teams involved in building and running CERN's accelerator complex. I have no doubt that we will overcome this setback with the same degree of rigour and application."

A faulty electrical connection between two of the accelerator's magnets is seen as the most likely cause of a large helium leak in sector 3-4 of the LHC tunnel Friday, Sept. 19. Before scientists can pinpoint the cause, they need to bring the section to room temperature and open the magnets involved for inspection, a process that takes three or four weeks. The superconducting electromagnets in the accelerator require liquid helium to keep them cool enough to operate, and helium becomes a liquid only at temperatures near absolute zero.

The time necessary for the investigation and repairs will be run into CERN's obligatory winter maintenance period, when the facility normally shuts down for repairs and updates, so restarting the accelerator will move to early spring 2009, officials said, after which will follow the generating of LHC beams.

"Particle accelerators such as the LHC are unique machines, built at the cutting edge of technology. Each is its own prototype, and teething troubles at the startup phase are therefore always possible," CERN said in a press release.

“The LHC is a very complex instrument, huge in scale and pushing technological limits in many areas,” said Peter Limon, who was responsible for commissioning the world’s first large-scale superconducting accelerator, the Tevatron at Fermilab on Long Island. “Events occur from time to time that temporarily stop operations, for shorter or longer periods, especially during the early phases.”

"I am confident that our colleagues at CERN will solve the problem speedily and we will continue to support them as much as we can," said Albrecht Wagner, director of Germany's DESY, home of the HERA superconducting particle accelerator, which ran from 1992 to 2007.

The LHC is expected to reveal a world of unknown particles, and LHC experiments could explain why those particles exist and behave as they do. They could reveal the origins of mass, shed light on dark matter, uncover hidden symmetries of the universe and possibly find extra dimensions of space. Its 17-mile racetrack for accelerating and colliding particles at nearly light speed is located deep underground near Geneva, Switzerland, and straddles the Swiss and French borders. It cost more than $8 billion to build.

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